Pharyngeal tissues in man and rat secrete a lipase which acts in the stomach, at pH 5.4, to hydrolyze triacylglycerol to the amphipathic products diacylglycerol, monoacylglycerol and fatty acids. This first step in digestion of dietary fat facilitates emulsification of triacylglycerol. The objectives of the project are: 1) isolate and purify pharyngeal lipase from tissues of rats and other species and from pharyngeal secretions of man, 2) characterize the mode of action of pharyngeal lipase, 3) study regulation and secretion of the enzyme, and 4) determine its role in fat digestion in both normal and diseased states in infants and adults. Recent findings show a five-fold purification, with 22% yield, of pharyngeal lipase from rat lingual serous glands. Protein containing lipolytic activity was precipitated with 60% saturated (NH4)2SO4 solution from the 100,000 x g supernate, resuspended in buffer solution (pH 5.4) and precipitated with cold acetone. This preparation will be used for further purification of pharyngeal lipase.